Core magnetic field and associated surface flow variations from 1999 to 2023

We present a recent update of the MCM series of magnetic field models and associated core surface flows. The models were derived sequentially from year 1999 to 2023, using magnetic satellite and ground observatory data. A linear Kalman filter approach and prior statistics based on numerical dynamo runs were used. The core field, the secular variation and the core surface flow models present the same characteristics as previous versions. In particular, filtering out the flow variation periods longer than 11.5 years leads to a filtered azimuthal flow with the same 7 years periodicities and patterns propagating westward by 60o longitude per year. The observed patterns are very likely related to the propagation of Magneto-Coriolis waves in the outer core.